User`s guide

3-8
3.3 GUTC Capacitor Board Installation
If the DCM-200 is allowed to originate calls, and the main ac power fails, power will be
supplied by a backup battery pack and the unit will immediately place a call to report an
“AC-OFF” alarm. Once the call is made the DCM-200 enters a power-saving sleep
mode and will remain there until ac power is restored.
When the main AC power fails a lithium battery pack provides backup power. The
battery’s voltage is 3.6Vdc when new and is designed to provide the short-duration,
high-current pulses required by the cellular radio. The battery pack is able to support a
minimum of 130 calls and has a long standby life of 8 – 10 years.
The g18 radio is specified to operate down to 3Vdc. When the lithium battery begins to
wear down the high-current pulses may cause the battery voltage to momentarily droop
below 3V, causing the radio to reset. To maintain proper regulation a small printed
circuit capacitor bank assembly (Figure 3-9) was designed to supply additional current
when needed. The Metretek stock number for this board is 1001-0307-001
The board plugs into an existing unused connector on the DCM-200’s processor board.
It is only required for g18-based units.
Figure 3-9
Top and Side View of Capacitor Board
Install the capacitor board as follows:
1) Disconnect the power connector from J1 on the GUTC board. It is not necessary